Clinical field efficacy of Effipro^® Duo in dogs naturally infested by ticks: a multi-centre, randomised, blinded, controlled study

Introduction 

The objective of the study was to confirm the clinical efficacy and safety of a fipronil-pyriproxyfen spot-on formulation (Effipro^® Duo, Virbac, Carros,
France) against natural tick infestations in client-owned dogs when compared to a positive control group (Frontline combo^®, Merial, Lyon, France).
This multi-centre study involved various clinics (study sites) within France and Germany and included 189 dogs.

Animals: The intention-to-treat (ITT) population contained 128 client-owned dogs treated with Effipro^® Duo and 61 treated with Frontline combo^®. The
per-protocol (PP) population contained 104 and 53 dogs, respectively, after exclusion (missing or late visits, unscheduled removal of ticks, etc.).
Recruited dogs had at least 3 live and attached (LA) ticks.

Schedule and treatment: Visits were performed on Days 0 (physical exam, tick count, weighing and treatment) and 7, 14, 21 and 28 (physical exam and
tick count). Counted ticks were collected and sent to a designated laboratory for tick species identification. Dogs received either treatment according to the
dog size (2-10 kg; 10.1-20kg; 20.1-40kg).

Analysis and statistics: Effectiveness was expressed as the percent reduction of LA ticks compared to the LA tick count number performed at day 0 (Wilcoxon-Mann-Whitney one-sided test
for non-inferiority).
The safety was judged by the occurrence of serious adverse events (SAEs), adverse events (AEs) and the local tolerance at the anatomical spot-on region. The experiment wise multiple level alpha
was defined as alpha = 0.025 one-sided (as required for confirmatory studies). The medical relevance of the differences between groups was quantified using the Mann-Whitney superiority
measure (MW, 0-1 scale). For non-inferiority the benchmark was defined as 0.36 (medium-sized inferiority), for superiority the benchmark was defined as 0.50 (equality) as described in Colditz et
al. 1988.

^{G. A. Colditz, J. N. Miller, F. Mosteller (1988): Measuring gain in the evaluation of medical technology. Intl. J.
of Technology Assessment in Health Care, 4, 637-642.}

Results 

Conclusion

In this field study condition, Effipro^® Duo had a greater acaricidal efficacy than Frontline combo^® on days 7 and 21. Effipro^® Duo was safe and effective for the treatment of tick infestation (European species) in dogs.